1. Field of the Invention
This invention relates to mixing apparatus for a plurality of different liquid materials.
2. Description of the Prior Art
It has heretofore been proposed to supply a plurality of fluid components to be combined to a common receiver or supply line. One such system is shown in U.S. Pat. No. 2,641,271 to Pressler. This may involve difficulties if one or more of the chemical materials is incompatible and the structure required is expensive.
Whitehouse, U.S. Pat. No. 3,442,453 shows a similar structure.
Jeffree, in U.S. Pat. No. 2,600,877, shows a device for mixing fluids in which a main pipe 20 has an interposed interrupter 24 for periodically blocking fluid passing through the main pipe 20. A branch pipe 22 leads into the main pipe through a one way valve 23 in a mixing chamber 26 beyond the interrupter 24 so that the inertia of the leading column of liquid beyond the interrupter 24 creates a suction to open the valve 23 and draw a small quantity of liquid B from the pipe 22.
In FIG. 3 two branch pipes 22 and 28 are shown as fed in series into the main pipe thus necessitating two mixing chambers 25 and 29, two inertia columns 21 and 30 and two interrupters 24 and 31.
In FIG. 4 is illustrated apparatus for mixing a very small proportion of fluid B with another fluid A.
Jeffree has no provisions for positive feeding of measured quantities of additives, no provisions for effective agitation to insure mixing, no control in the event of exhaustion of one of the materials to be added and no shut-down when a predetermined quantity of the proper mixture is available.
Stearns, in U.S. Pat. No. 2,645,463, shows method and apparatus for continuous flow mixing. In FIG. 3, a common conduit 3 for fluids has conduit elements 11, 12 and 13 with discharge end portions 11a, 12a and 13a, respectively, opening into the conduit 3. Each of the individual conduit members has structure therein intended for inducing turbulent flow, orifice plate members 11b, 12b and 13b being provided for this purpose. As shown two fluid streams are introduced into the common conduit 3 by the conduits 11 and 12 to be mixed in the zone 14. The stream is advanced past baffle members 15 to induce turbulent flow in the previously combined stream and to homogenize the mixture in the zone 14 prior to introduction of fluid through conduit 13 and its orifice plate member 13b. The reference to homogenizing indicates an attempt to combine substantially immiscible or difficultly miscible materials rather than combining soluble chemical materials. Stearns appears to have a continuously flowing stream and is silent as to the manner of supplying the fluid through the individual conduits and does not undertake to supply any measured quantities of materials. Careful sizing of the main conduit of Stearns, and the conduit elements with their orifices, would be required to induce turbulent flow of a character to achieve the mixing and homogenization desired by Stearns if in fact it could be achieved. If the quantities to be introduced were very small in proportion to the fluid stream there would be a serious problem as to the effectiveness of these small quantities to produce turbulence at a mixing zone and serious doubt as to the efficiency of the distribution of the material thus added.
Stearns also has no provisions for shut-off if a material to be added was exhausted and no provisions for shut-off when an adequate supply of the mixture was available.